text: #!/usr/bin/env python
  # coding=utf-8
  
  # 科学计算模块
  import numpy as np
  # python可视化模块
  import matplotlib.pyplot as plt
  
  x = np.linspace(0, 1, 500)
  y = np.sin(4 * np.pi * x) * np.exp(-5 * x)
  
  fig, ax = plt.subplots()
  
  ax.fill(x, y, zorder=10)
  ax.grid(True, zorder=5)
  plt.show()